Name of the Trial
Phase II Study of Flavopiridol in Patients with Previously Treated B-Cell Chronic Lymphocytic Leukemia (CLL) or Prolymphocytic Leukemia Arising from CLL (CLLRC-OSU-0491). See the protocol summary at http://cancer.gov/clinicaltrials/CLLRC-OSU-0491. This trial previously appeared in the October 25, 2005, NCI Cancer Bulletin.

Principal Investigator
Dr. John Byrd, Ohio State University and the CLL Research Consortium

Why This Trial Is Important
Chronic lymphocytic leukemia (CLL) is a blood cancer in which the bone marrow produces malignant lymphocytes, a type of white blood cell. CLL responds to standard treatments, such as chemotherapy and monoclonal antibody therapy, but the disease will recur and eventually become resistant to therapy.

In this trial, researchers are testing a drug called flavopiridol (also known as alvocidib) in patients with relapsed CLL. Flavopiridol was originally tested in the 1980s, after laboratory studies showed it had activity against CLL and other types of cancer cells. In these trials, however, the drug was not effective when given intravenously over 1 to 3 days. Subsequently, interest in it waned.

Recently, Ohio State University (OSU) researchers showed that the effectiveness of flavopiridol may depend on its route of administration, and a phase I trial testing a large dose of the drug given over 30 minutes followed by an additional dose given over 4 hours has shown promising results in patients with previously treated CLL. The current phase II trial seeks to confirm these results with a larger group of patients.

"Approximately 50 percent of patients who had relapsed after multiple treatments responded to flavopiridol in our study. More importantly, this drug is highly active in patients with high-risk genetic features who respond to few if any standard treatments," said Dr. Thomas Lin of OSU, principal investigator of the phase I trial.

Who Can Join This Trial
Researchers will enroll 17 to 32 patients aged 18 or over with relapsed B-cell CLL or a related cancer called prolymphocytic leukemia. See the list of eligibility criteria at http://cancer.gov/clinicaltrials/CLLRC-OSU-0491.

Study Site and Contact Information
Study sites in the United States are recruiting patients for this trial. See the list of study sites at http://cancer.gov/clinicaltrials/CLLRC-OSU-0491, or call NCI's Cancer Information Service at 1-800-4-CANCER (1-800-422-6237). The toll-free call is confidential.